1. They were made from actual women. He was made from rats and weasels
2. How do you know he isn’t? So far he’s been doing a good job of covering the important bits. Besides, if he wasn’t “anatomically correct”, there wouldn’t be anything to cover.

No, he explained (before this, no spoilers here) that Jin’s mom knew how to make golems because she made HIM. He doesn’t know what from, just mentioned that she “ran experiments on rats and weasels”. He’s not necessarily the first, but he’s the first of the 5 that we know about thus far (second being Jin’s mom herself).